Computational and Physical Simulation Methods for Off-Line Validation of Soft Magnetic Composite Impeder Performance

High-frequency induction (HFI) tube welding is an energy-intensive process in which the impeder plays a critical role in power utilization. Conventional ferrite cores often operate near magnetic saturation in small-diameter applications, which can limit efficiency and process stability, particularly under high production rates. Soft magnetic composites (SMCs) offer higher saturation potential, but their internal behavior under welding conditions is difficult to assess experimentally. To address this challenge, this study proposes a methodology for evaluating impeder performance without relying on industrial-scale trials. The approach combines a three-dimensional electromagnetic–thermal model of the welding process with a reduced two-dimensional model for detailed analysis. The predictive capability of the 3D model was assessed through comparison with experimental measurements, providing an initial experimental validation under the investigated operating conditions. Based on this reference, a 2D model is derived by removing the tube and introducing an equivalent correction factor, obtained through comparison with the 3D results, to account for its influence. The reduced model is then used to investigate the internal thermal behavior of a representative SMC (Fluxtrol 50) impeder. The results reveal a pronounced hotspot in the region corresponding to the inductor position, with significantly higher temperatures than in other areas, indicating a critical thermal limitation for operation. The proposed methodology provides a reliable and efficient framework for analyzing and designing impeder systems, offering a practical alternative to costly industrial testing.